Device for perforating elastic sheet material



Inventor #EIVIIVG Attorneys FIG/.-

F/GZ I I -24- H EWING DEVICE FOR PERFORATING ELASTIC SHEET MATERIAL Flled Feb 4, 1947 Oct. 7, 1952 Patented Oct. 7, 1952 UNITEDv STATES PATENT OFFICE DEVICE FOEPERFORATING ELASTIC- SHEET MATERIAL This invention relates to a device iorproduo ing in elastic sheet materials perforations spaced state'- through the said perforator;

In its preferred form the invention consists in a device which comprises a pair of nip rollers adapted to' draw and forward the sheet material from a supply continuously, at second pair of nip rollers adapted to draw the sheetma terials continuously from the first pair of hip rollers and maintain it in a stretched statewhile travelling between the two pairs of nip rollers, and between them a perforator through which the sheet'material passes and an intermediate movably mounted and preferably free running roller ada ted to bear on and depress the sheet materials The intermediate roller maybe situated on either side of the perforator, but is preferably between the perforator and the nip rollers through which the sheet material leaves the device.

The lowerroller of each pair 01" mp rollers may be driven from the same shaft as the per forator, for exampl'e'by' chain and sprocket, while the upper roller or each pair maybe free-running' and arranged to press on' the lower roller; by: its own weight or otherwise; so as to grip the sheet material and prevent slip. The up per roller may for example run in bearings carried by pivoted arms. In order to impart the desired degree of'st'retch to thematerial the lower roller of' thesecond pair is driven at a slightly higher peripheral speed than that of the first pair; for example it may be driven at the same angular'veloc'ity" and besomewhat larger in diameterapreferably by" about 245%. The intermediateroller may be spring-weighted, but it is preferable that it should be freely mounted and. caused to beacon the material by its" own weight; For example it may be mounted on a pair or. arms pivoted at some suitable point, which may with advantage be approximately in GIYS 2 4* Claims. (Cl. E b -89) The perforator' may comprise upper and lower guide plates, between which the sheet material is caused to travel, and a set of punches arranged 0 for example transversely across the width of the material and moving through clearance holes in the upper guideplate into-corresponding clearanceholes in the lower guide plate. The lower guide plate is preferably positioned slightly abovethe direct line between the two pairs of hip rollers. d a I I If desired the intermediate roller may be omitted; but I have found that itis not then possible always to achieve regular spacingoi the perforations. In the absence-or thisroller there frequently occur irregularities of spacing'vvhich appear to be connected with irregularities in the thickness and in the tackiness or the sheet material;

Perforating devices" constructed in accordance with the invention are es ecially useful for per forating' at re ular intervals thin and thus easily stretched elastic sheets having a basis'oi natural rubber or a rubber substitutesuch for example as plasticized polyvinyl chloride, styrene olymers and diolefine polymers (ihc1iidiilg co"- polymer's), and of elastic laminated sheet material consisting for example of a thin sheet of rubber or of a rubber-s bstitute united witha stretchable woven or knitted fabric; Other laminated materials maybe made by'fflrst perforating' a thin sheet of rubber orof a rubber substitute by means ofthe device described above, and then uniting the perforated sheet with a suitable imperforate' stretchable woven or knitted fabric which is sufiiciently'loosely woven or knitted to permitthe free passage of air; for example laminated material very suitable for corset" manufacture may be made by uniting a perforatedsheet of a plasticize'd polyvinyl chloride composition with a stretchable loosely woven or knitted fabric having a basis of a cellulose" ester or other; in particular cellulose aeetatei A device rerperiorating elastic shl? material in accordance with the inventionis illustrated in the accompanying: drawings; which Figure 1- represents a sectional view of" the device asa Whole, and Figuresz and 3* are-side andplanviews respectively of the means" whereby the punches or the erforator are held in position. 'ihede vice comprises alskeletorr irameworli' #orr'w ch are mounted drivenfeed rol le'rs 5 and B'of'sligh ly dilfererit' diameters; arms 1- and B f'reely p'i'v oted in bearings Sand {0 and carryin seem ning rollers l I and I2 restin on thedriven rollers 5 andG respectively, arms 13- freely'pivot'e'd through the device, and a perforator it.

3 in the bearings 9 and carryin a free-running intermediate roller M adapted to rest on and be supported by the sheet material I5 DQ188128 T e feed rollers 5 and 6 are driven at the same angular velocity by means of a motor 26 driving chains 21 and 28, which pass over sprockets 29 and 30 mounted at one end of each of the rollers 5 and 6, respectively. The perforator comprises a lower guide plate ll and an upper guide plate I [8, both provided with clearance holes for punches so arranged that each hole in the upper guide plate I8 is opposite a hole in the lower guide plate H. The lower guide plate ii is at a level slightly above that of the nips of the pairs of rollers 5 and ii, and 6 and 82 respectively. Above the guide plates is positioned a carrier bar 2t, 2! attached to and below a spring-mounted pressure bar IS; the carrier bar is capable of vertical reciprocating movement and is split longitudinally into a section 20, which is permanently attached to the lower face of the pressure bar It, and a section 2i, which is removable at will. The sections and M are provided with corresponding grooves which, when the section 2! is in position, form sockets adapted to hold removable punches 22 in positions corresponding to the clearance holes in the guide plates. The pres sure bar lfi carries on its upper face a bracket 23, which in turn carries roller cam followers 26 which are in contact with and adapted to be depressed by a cam driven from the same shaft as the rollers 5 and (i.

In operation, the elastic sheet material is continuously fed either through the nip of the rollers 5 and ii, under the intermediate roller M, between the guide plates ii and 58 of the perforator, and finally through the nip of the rollers 6 and E2, or in the reverse direction. While both these alternatives give good results, the second is preferred, as it has been found to cause even more regular spacing of the perforations. In either case, the diameter of the driven roller over which the material passes when leaving the device is larger than thatof the driven roller over which it passes when entering the device by an amount such that sheet material passing through the device is stretched to a degree substantially below its breaking stretch, V

The free running rollers ii and it; bear on the driven rollers 5 and ii sufficiently heavily to pre= vent the sheet material slipping in the nip of either pair of rollers.

Having described my invention, what I desire to secure by Letters Patent is:

1. A device for perforating elastic sheet rnatw rial, which comprises a pair of nip rollers adapted to draw and forward sheet material from a supply, a second pair of nip rollers spaced'from and parallel to the first and adapted to draw sheet material from the first pair, means for continuously driving at least one of the first pair of nip rollers, means for continuously driving at least one of the second pair of nip rollers at a predetermined peripheral speed at least 2 higher than that of the first pair and in the same direction as the corresponding roller of the first pair, a perforator positioned between the two pairs of nip rollers and comprising a perforated guide plate over which the sheet material passes and reciprocating punches which in one extreme position are well clear of the guide plate and in the other extend into the perforations in the guide plate, and between one of the pair of hip rollers and the perforator a single jockey roller parallel to the nip rollers and carried in an independently-movable mounting such that in the absence of sheet material passing through the device the jockey roller will take up a position substantially below the plane in which lie the nip of the nip rollers next to the jockey roller and that edge of the upper surface of the guide plate which is the nearer to the jockey roller.

2. A device for perforating elastic sheet material, which comprises a pair of nip rollers adapted to draw and forward sheet material from a supply, a second pair of nip rollers spaced from and parallel to the first and adapted to draw sheet material from the first pair, means for continuously driving at least one of the first pair of nip rollers, means for continuously driving at least one of the second pair of nip rollers at a predetermined peripheral speed at least 2% higher than that of the first pair and in the same direction as the corresponding roller of the first pair, a perforator positioned between the two pairs of nip rollers and comprisin a perforated guide plate over which the sheet material passes and reciprocating punches which in one extreme position are well clear of the guide plate and in the other extend into the perforations in the guide plate, and between one of the pair of nip rollers and the perforator a single, free running jockey roller parallel to the nip rollers and carried in an independently movable mounting such that in the absence of sheet material passing through the device the jockey roller will take up a position substantially below the plane in which lie the nip of the'nip rollers next to the Jockey roller and that edge of the upper surface of the guide plate which is the nearer to the jockey roller. 3. A device for perforating elastic sheet material, which comprises a pair of nip rollers adapted to draw and forward sheet material from a supply, a second pair of nip rollers spaced from and parallel to the first and. adapted to draw sheet material from the first pair, means for continuously drivin at least one of the first pair of nip rollers, means for continuously driving at least one of the second pair of nip rollers at a predetermined peripheral speed at least 2% higher than that of the first pair and in the same direction as the corresponding roller of the first pair, a perforator positioned between the two pairs of nip rollers and comprising a perforated guide plate over which the sheet material passes and reciprocating punches which in one extreme position are well clear of the guide plate and in the other extend into the perforations in the guide plate, and between the second pair of nip rollers and the perforator, a single jockey roller parallel to the nip rollers and carried in an independently movable mounting such that in the absence of sheet material passing through the devices the jockey roller will take I up a position substantially below the plane in which lie the nip of the second pair of nip rollers and that edge of the upper surface of the guide plate which is nearer to the jockey roller.

l. A device for perforating elastic sheet material, which comprises a pair of hip rollers adapted to draw and forward sheet material from a supply, a second pair of nip rollers spaced from'and parallel to the first and adapted to draw sheet material from the first pair, means for continuously driving at least one of the first pair of nip rollers, means for continuously driving at least one of the second pair of nip rollers at a predetermined peripheral speed at least 2 higher than I 5 that of the first pair and in the same direction as the corresponding roller of the first pair, a perforator positioned between the two pairs of nip rollers and comprising a perforated guide plate over which the sheet material passes and reciprocating punches which in one extreme position are well clear of the guide plate and in the other extend into the perforations in the guide plate, and between the second pair of nip rollers and the perforator, a single, free running jockey roller parallel to the nip rollers and carried in an independently movable mounting such that in the absence of sheet material passing through the devices of the jockey roller will take up a position substantially below the plane in which lie 15 the nip of the second pair of nip rollers and that edge of the upper surface of the guide plate which is nearer to the jockey roller.

HENRY EWING.

6 v REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 915,537 Bancroft et a1. Mar. 16, 1909 1,048,560 McCall Dec. 31,. 1912 1,441,359 Langston Jan, 9, 1923 1 ,905,446 Dewey et a1. Apr. 25 1933 2,143,507 Chandler Jan. 10, 1939 FOREIGN PATENTS Number Country Date 2,461 Great Britain May 16, 1883 1,501 Great Britain Jan. 20, 1911 

